Data Bus
MSC8113 Reference Manual, Rev. 0
Freescale Semiconductor
14-3
14.1 Data Bus
The DSI data bus is organized from left to right in ascending order, so Bit 0 is the msb. The bytes
are organized the same way, with byte lane 0 for the MSB. The width of the data transfer does not
imply the operand’s data structure. For example, a 16-bit data transfer on a 32-bit bus contains
one data structure of 16 bits or two data structures of 8 bits. The operand data structure
determines the order of the bytes in the data transfer, depending on the Little- or Big-Endian
mode (see Section 14.2.4).
14.1.1 Data Bus Width
The
DSI64
signal is sampled during
PORESET
signal deassertion and defines the data bus width as
64-bit or 32-bit (see the description of DSR[DSI64] on page 14-35). Table 14-1 defines the
possible data transfers in the 64-bit data bus mode.
Table 14-1. Data Transfers for Single Accesses in 64-bit Data Bus Mode
Transfer
Size
Byte Enable
[0–7]
Data Bus Byte Lanes
HD[0–7]
HD[8–15]
HD[16–23] HD[24–31] HD[32–39] HD[40–47] HD[48–55] HD[56–63]
Byte0
Byte1
Byte2
Byte3
Byte4
Byte5
Byte6
Byte7
8-bit
0 1 1 1 1 1 1 1 8-bit data
—
—
—
—
—
—
—
1 0 1 1 1 1 1 1
—
8-bit data
—
—
—
—
—
—
1 1 0 1 1 1 1 1
—
—
8-bit data
—
—
—
—
—
1 1 1 0 1 1 1 1
—
—
—
8-bit data
—
—
—
—
1 1 1 1 0 1 1 1
—
—
—
—
8-bit data
—
—
—
1 1 1 1 1 0 1 1
—
—
—
—
—
8-bit data
—
—
1 1 1 1 1 1 0 1
—
—
—
—
—
—
8-bit data
—
1 1 1 1 1 1 1 0
—
—
—
—
—
—
—
8-bit data
16-bit
0 0 1 1 1 1 1 1
16-bit data
—
—
—
—
—
—
1 1 0 0 1 1 1 1
—
—
16-bit data
—
—
—
—
1 1 1 1 0 0 1 1
—
—
—
—
16-bit data
—
—
1 1 1 1 1 1 0 0
—
—
—
—
—
—
16-bit data
32-bit
0 0 0 0 1 1 1 1
32-bit data
—
—
—
—
1 1 1 1 0 0 0 0
—
—
—
—
32-bit data
64-bit
0 0 0 0 0 0 0 0
64-bit data
Notes: 1.
Lanes specified as 8-, 16-, 32-, or 64-bit data is read or written during the bus transaction.
2.
Lanes specified with “—” are ignored during writes and driven with undefined data during reads.
3.
If the DCR[BEM] bit (see page 14-29) is cleared (0), only the HWBS0, HDBS0, HWBE0, or HDBE0 signal is used.
The specific signal used depends on the configured access mode (that is, Asynchronous Dual Strobe mode write,
Asynchronous Single Strobe mode read or write, Synchronous Dual Strobe mode write, or Synchronous Single
Strobe mode read or write, respectively). For details, see Section 14.3.1 and Section 14.3.2.
Summary of Contents for MSC8113
Page 1: ...MSC8113 Reference Manual Tri Core 16 Bit Digital Signal Processor MSC8113RM Rev 0 May 2008 ...
Page 20: ...MSC8113 Reference Manual Rev 0 xx Freescale Semiconductor Contents ...
Page 28: ...MSC8113 Reference Manual Rev 0 xxviii Freescale Semiconductor ...
Page 56: ...MSC8113 Reference Manual Rev 0 1 28 Freescale Semiconductor MSC8113 Overview ...
Page 76: ...MSC8113 Reference Manual Rev 0 2 20 Freescale Semiconductor SC140 Core Overview ...
Page 134: ...MSC8113 Reference Manual Rev 0 4 30 Freescale Semiconductor System Interface Unit SIU ...
Page 168: ...MSC8113 Reference Manual Rev 0 6 18 Freescale Semiconductor Boot Program ...
Page 180: ...MSC8113 Reference Manual Rev 0 7 12 Freescale Semiconductor Clocks ...
Page 260: ...MSC8113 Reference Manual Rev 0 8 80 Freescale Semiconductor Memory Map ...
Page 300: ...MSC8113 Reference Manual Rev 0 9 40 Freescale Semiconductor Extended Core ...
Page 304: ...MSC8113 Reference Manual Rev 0 10 4 Freescale Semiconductor MQBus and M2 Memory ...
Page 308: ...MSC8113 Reference Manual Rev 0 11 4 Freescale Semiconductor SQBus ...
Page 590: ...MSC8113 Reference Manual Rev 0 17 46 Freescale Semiconductor Interrupt Processing ...
Page 614: ...MSC8113 Reference Manual Rev 0 18 24 Freescale Semiconductor Debugging ...
Page 622: ...MSC8113 Reference Manual Rev 0 19 8 Freescale Semiconductor Internal Peripheral Bus IPBus ...
Page 724: ...MSC8113 Reference Manual Rev 0 21 32 Freescale Semiconductor UART ...
Page 920: ...MSC8113 Reference Manual Rev 0 25 150 Freescale Semiconductor Ethernet Controller ...
Page 1171: ...MSC8113 Reference Manual Rev 0 Freescale Semiconductor C 61 EF wait_rts P 01077FFC 9F rts 71 ...
Page 1172: ...MSC8113 Reference Manual Rev 0 C 62 Freescale Semiconductor MSC8113 Boot Code ...
Page 1202: ...MSC8113 Reference Manual Rev 0 Index 30 Freescale Semiconductor Index ...